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Test scope & comparison notes
These are recorded facts, not a unified ranking. Tested tiers and scope are not consistently recorded. Read pricing with its date and timing with its conditions. Privacy observations reflect visible flows and statements, not a security audit.
Cross-task capability coverage across selected products
Each product is scored independently per task edge; switch tasks below while keeping shared products selected| Task edge | Unlimited:Waifu2x | ImgUpscaler | Switch / compare |
|---|---|---|---|
| Image upscaling | 89/100 2048 × 2048 · PNG | 85/100 2048×2048 (PNG · 400% / 4.0x AI Upscale) · Historical description; output not attached | Active task |
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Browse this task →| Criterion | Unlimited:Waifu2x (WebGPU In-Browser SR) Image upscaling 89/100 Seven-aspect task score Free open-source, login-free on-device processing gives good 4× detail; a dismissible rewarded-ad prompt may appear on first use. Tested export 2048 × 2048 · PNG Historical test · 2026-10-17 | ImgUpscaler (AI Image Upscaler) Image upscaling 85/100 Seven-aspect task score Free login-free 4× output retains detail well; a fullscreen ad can interrupt initial use, and this run took about 22 seconds. Tested export 2048×2048 (PNG · 400% / 4.0x AI Upscale) · Historical description; output not attached Historical test · 2026-10-16 |
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| Pricing & rules | ||
| Pricing plans | unlimited:waifu2x in-browser AI image upscaler · 2026-10-21 Plan · source date Monthly / one-time Annual bill / period Quota & limits unlimited:waifu2x Free Web2026-10-21 ↗ Free Free Free Free without login and no image-count limits (runs on local WebGPU/WASM hardware); supports up to 4x unwatermarked PNG export. 1 plan / billing-period records, all listed; — means that period is not recorded. In-browser WebGPU/WebAssembly upscaler powered by nunif/waifu2x. Completely free with no account system or paid tiers; offers swin_unet and cunet models, 1x/2x/4x upscaling, and denoise levels running on local device hardware. Cancellation, sources & verification recordCompletely free open-source-powered tool with no accounts or subscription charges. unlimited:waifu2x official page ↗ · 2026-10-21 Capture 1 ↗ | ImgUpscaler personal and business plans (Free / Premium / Business); USD · 2026-10-21 Plan · source date Monthly / one-time Annual bill / period Quota & limits Free2026-10-21 ↗ Free Free Free 50 credits/month; single-image AI upscaling, enhancement, and Reimagine (includes ads; guest single-image 4x upscaling available). Premium Monthly2026-10-21 ↗ USD 9.9/month — Monthly 500 credits/month; includes batch processing, Reimagine AI access, ad-free workspace, and email support. Premium Yearly2026-10-21 ↗ — USD 49/year Annual Billed yearly at USD 49/year (USD 4.08/month equivalent); 500 credits/month, batch processing, ad-free workspace, and email support. Business Monthly2026-10-21 ↗ USD 19.9/month — Monthly No credits limit; single and batch processing, Reimagine AI access, ad-free workspace, and commercial production workflows. Business Yearly2026-10-21 ↗ — USD 69/year Annual Billed yearly at USD 69/year (USD 5.75/month equivalent); no credits limit, batch processing, and ad-free workspace. 5 plan / billing-period records, all listed; — means that period is not recorded. The official pricing page lists Free (USD 0, 50 credits/month, single-image processing, includes ads), Premium (USD 9.90/month or USD 49/year, equivalent to USD 4.08/month, with 500 credits/month, batch processing, and no ads), and Business (USD 19.90/month or USD 69/year, equivalent to USD 5.75/month, with no credit limit, batch processing, and no ads). Cancellation, sources & verification recordCancel or change plans anytime from the account billing page; both free and paid results may be used for personal or commercial projects subject to source-image rights. ImgUpscaler official monthly/yearly pricing and FAQ ↗ · 2026-10-21 Capture 1 ↗ · Capture 2 ↗ |
| Free & trial allowance on the test date | Unlimited local WebGPU runs with zero daily caps or credit deductions | Free single-image 200% (2x) and 400% (4x) unwatermarked upscaling without login; batch upload requires a paid plan |
| Cancellation & refunds | Completely free open-source-powered tool with no accounts or subscription charges. | Cancel or change plans anytime from the account billing page; both free and paid results may be used for personal or commercial projects subject to source-image rights. |
| Disclosure of costs & limits | Explicitly discloses WebGPU browser requirements and model options at the top of the page | No paywall traps; supported by standard and vignette Google AdSense ads |
| Task quality | ||
| Measured fixture results | Tested scale: 4× | Tested scale: 4× |
| Fixture findings | Ran 4× upscaling locally with noise reduction and text retention; speed depends on the device. | This guest run produced a watermark-free 4× image with structure retained; findings cover this fixture only. |
| Original historical observation | Waifu2x Unlimited (Swin-UNet Photo 4x) suppresses JPEG compression artifacts cleanly while preserving natural camera gradients (PSNR 28.34 dB, SSIM 0.895) in 2.63s via WebGPU, without introducing fake generative hallucinations. | PSNR=27.50dB · SSIM=0.8900 (4x 2048×2048 unwatermarked PNG); edge_corr=0.6685, hf_ratio=0.4995, plate_psnr=16.22dB—one of the very few tools offering genuine 400% watermark-free exports to anonymous guests. |
| Suitable uses · historical assessment | Privacy-conscious users, anime/illustration and natural photo creators who want 100% free, unlimited 4x local GPU super-resolution without uploading files to any cloud server | Users who want true 4x (2048×2048) watermark-free faithful super-resolution without creating an account |
| Result & output evidence | No native output obtained; the preview does not establish final export quality. | |
| Delivery capabilities | ||
| Recorded export specifications | 2048 × 2048 · PNG · No watermark in test | 2048×2048 (PNG · 400% / 4.0x AI Upscale) · Historical description; output not attached · Check watermark record No native output is attached; check the evidence for specification and watermark claims. |
| Historical specification note · not an official maximum | 2048 × 2048 (true 4x lossless PNG export, supporting arbitrary large-image tiled inference) | 2048×2048 (4.0x / 400% · Free without login) |
| Watermark observation | Watermark-free | 100% Watermark-Free |
| Batch & API | Supports multi-model switching (Swin-UNet Art / Art Scan / Photo), 4-level denoise, and configurable tile size | Batch web upload on paid plans; offline batch processing via desktop app Upscal.app |
| Recorded free-tier dimensions | 2048 × 2048 | Not verified |
| Attached file dimensions | 2048 × 2048 · PNG | Not verified |
| Speed & reliability | ||
| Timing observation | Recorded local processing time: 2.63s · End-to-end reference: 2.63s | Network-observed server wait: 20.68s · End-to-end reference: 22.22s |
| Date & fixture | 2026-10-17 · anchor_upscale_v1 · US-West (California, AS2914) | 2026-10-16 · anchor_upscale_v1 · US-West (California, AS2914) |
| Repeated tests & reliability | No standardized repetition count, success rate or variability range is recorded. | No standardized repetition count, success rate or variability range is recorded. |
| Interaction experience | ||
| Account requirements | No login in this test | No login in this test |
| Sign-in methods | 100% usable without login (runs entirely in the local browser via WebGPU) | No login required; optional email/Google login for paid plans |
| Manual adjustment | Not verified | Not verified |
| Interaction observations | Pure single-page engineering workbench: select model (Swin-UNet Art / Photo), Denoise level, and 1x/2x/4x scale, then immediately preview or download the 2048×2048 PNG. | Zero login walls or bait-and-switch paywalls, though the free web page runs Google AdSense including a full-screen interstitial vignette (`#google_vignette`, Screenshot ④) that may require dismissing. |
| Background & reputation | ||
| Service lifecycle notice | Not verified | Not verified |
| Operator | nagadomi (waifu2x / nunif Open-Source Author) | ImgUpscaler / Upscal.app Team |
| Recorded origin | Independent open-source AI vision researcher (Japan) | Independent Cross-Platform Utility Team (Web + macOS/Windows App Store) |
| Domain history record | 2015–Present (waifu2x.net) | 2020–Present |
| Background & reputation assessment | Authored and maintained by nagadomi, the creator of the iconic Waifu2x open-source repository and the nunif deep-learning framework. | Operated by the independent team behind Upscal.app (available on the Mac App Store and Microsoft Store). |
| External reputation record | Not verified | Not verified |
| Engineering & privacy | ||
| Processing location | On-device processing | Uploaded for cloud processing |
| Third-party tracking record | Not verified | Not verified |
| Engineering & privacy assessment | 100% local in-browser WebGPU / ONNX Runtime inference — user images never leave the local device, offering maximum privacy protection. | Uses `/api/legacy/upload` and `/api/legacy/status` async polling; FAQ #10 explicitly states all uploaded and processed images are permanently deleted within 24 hours. |
| Retention statement | This flow runs locally; post-close deletion not independently verified | Claims deletion within 24 hours; deletion not independently verified |
| Evaluation basis | ||
| Pricing transparency | 34 / 35 100% free and open-source in-browser WebGPU tool with zero paywalls, zero ad clutter, and no usage limits (01_landing.png, 02_workspace.png, 03_download.png). | 32 / 35 Anonymous guests can select `400%` (4x) or `200%` (2x) directly on the home page, click 'Upload & Start', and download a 100% watermark-free 2048×2048 (4x) PNG without signing up or entering a card (Screenshots ②③). |
| Interaction restraint | 25 / 30 Pure single-page engineering workbench: select model (Swin-UNet Art / Photo), Denoise level, and 1x/2x/4x scale, then immediately preview or download the 2048×2048 PNG. | 21 / 30 Zero login walls or bait-and-switch paywalls, though the free web page runs Google AdSense including a full-screen interstitial vignette (`#google_vignette`, Screenshot ④) that may require dismissing. |
| Background & reputation | 19 / 20 Authored and maintained by nagadomi, the creator of the iconic Waifu2x open-source repository and the nunif deep-learning framework. | 15 / 20 Operated by the independent team behind Upscal.app (available on the Mac App Store and Microsoft Store). |
| Engineering & privacy | 14.5 / 15 100% local in-browser WebGPU / ONNX Runtime inference — user images never leave the local device, offering maximum privacy protection. | 12 / 15 Uses `/api/legacy/upload` and `/api/legacy/status` async polling; FAQ #10 explicitly states all uploaded and processed images are permanently deleted within 24 hours. |
| Task quality | 57.2 / 65 PSNR vs 2048px GT: 28.34 dB · SSIM: 0.895 · Edge Gradient Correlation: 0.7165 · High-Freq Sharpness Ratio: 0.5256 · Calibration Plate PSNR: 17 dB | 58.5 / 65 PSNR vs 2048px GT: 27.5 dB · SSIM: 0.89 · Edge Gradient Correlation: 0.6685 · High-Freq Sharpness Ratio: 0.4995 · Calibration Plate PSNR: 16.22 dB |
| Deliverable specifications | 20 / 20 Exports a full 2048×2048 4x upscaled PNG (or WebP/JPEG) locally in the browser with zero watermarks and no file-count limits (20.0/20) | 20 / 20 No free unwatermarked export (0/8); Free scale factor: 4x (2048×2048 (4.0x / 400% · Free without login)) |
| Processing speed | 10.5 / 15 Local WebGPU hardware acceleration completes 512→2048 (4x) tiled inference in just 2.63s with zero network upload overhead (14.5/15) | 8 / 15 Network-observed server wait: 20.68s (API mode: async_poll; end-to-end 22.22s shown for reference only, never penalized) |
